In a conventional electromagnetic relay, there is a contact device including a fixed terminal provided with a fixed contact, a movable terminal provided with a movable contact configured to attach to and detach from the fixed contact, a cylindrical movable shaft having an end to which the movable contact is fixed, a movable iron core fixed to the other end of the movable shaft, a fixed iron core which is externally inserted into the movable shaft and faces the movable contact and the movable iron core, an electromagnet device which generates magnetic attraction force between the fixed iron core and the movable iron core, thus causing the movable iron core to move and reach the fixed iron core, and a return spring which is interposed between the movable iron core and the fixed iron core and elastically biases the movable iron core so as to be separated from the fixed iron core. In the contact device, the electromagnetic device includes, inside a cylindrical shaft portion thereof, the movable shaft, the fixed iron core, a coil bobbin into which the movable iron core is inserted, a coil which is wound around a shaft portion of the coil bobbin, and a yoke configured to accommodate the coil and the coil bobbin inside thereof and provided with a through hole which is formed in a center of a bottom surface and configured to communicate with a hole of the shaft portion of the coil bobbin. In the contact device, a rising piece which rises toward an inside of the shaft portion from a circumferential edge of the through hole is provided in the yoke. In the contact device, the movable iron core includes a larger diameter portion which faces the fixed iron core along a moving direction and a smaller diameter portion which has a smaller diameter than the larger diameter portion and faces the rising piece in a direction orthogonal to the moving direction. Such a conventional contact device is, for example, disclosed in Japanese Unexamined Patent Publication No. 2006-310249.
However, in the contact device, when impact force is externally applied in an axial direction of the cylindrical movable shaft during non-excitation, for example, there is a possibility that the movable contact comes into contact with the fixed contact due to the force of inertia of the whole movable parts and thus the contact device malfunctions. For this reason, in order to increase an impact resistance, a measure of increasing biasing force with an increase in spring constant of the return spring is considered. However, in terms of securing smooth operation property, it is necessary to increase an attraction force of the electromagnet device rather than the increase of the biasing force of the return spring. For this reason, there is a problem that a high application voltage needs to be applied to drive the movable parts and thus power consumption increases.